<?php

/**
 * @link http://www.yiiframework.com/
 * @copyright Copyright (c) 2008 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

namespace yii\web;

use Yii;
use yii\base\Exception;
use yii\base\ErrorException;
use yii\base\UserException;
use yii\helpers\VarDumper;

/**
 * ErrorHandler handles uncaught PHP errors and exceptions.
 *
 * ErrorHandler displays these errors using appropriate views based on the
 * nature of the errors and the mode the application runs at.
 *
 * ErrorHandler is configured as an application component in [[\yii\base\Application]] by default.
 * You can access that instance via `Yii::$app->errorHandler`.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @author Timur Ruziev <resurtm@gmail.com>
 * @since 2.0
 */
class ErrorHandler extends \yii\base\ErrorHandler
{

	/**
	 * @var integer maximum number of source code lines to be displayed. Defaults to 19.
	 */
	public $maxSourceLines = 19;

	/**
	 * @var integer maximum number of trace source code lines to be displayed. Defaults to 13.
	 */
	public $maxTraceSourceLines = 13;

	/**
	 * @var string the route (e.g. 'site/error') to the controller action that will be used
	 * to display external errors. Inside the action, it can retrieve the error information
	 * using `Yii::$app->errorHandler->exception. This property defaults to null, meaning ErrorHandler
	 * will handle the error display.
	 */
	public $errorAction;

	/**
	 * @var string the path of the view file for rendering exceptions without call stack information.
	 */
	public $errorView = '@yii/views/errorHandler/error.php';

	/**
	 * @var string the path of the view file for rendering exceptions.
	 */
	public $exceptionView = '@yii/views/errorHandler/exception.php';

	/**
	 * @var string the path of the view file for rendering exceptions and errors call stack element.
	 */
	public $callStackItemView = '@yii/views/errorHandler/callStackItem.php';

	/**
	 * @var string the path of the view file for rendering previous exceptions.
	 */
	public $previousExceptionView = '@yii/views/errorHandler/previousException.php';

	/**
	 * Renders the exception.
	 * @param \Exception $exception the exception to be rendered.
	 */
	protected function renderException($exception)
	{
		if (Yii::$app->has('response'))
		{
			$response = Yii::$app->getResponse();
		}
		else
		{
			$response = new Response();
		}

		$useErrorView = $response->format === Response::FORMAT_HTML && (!YII_DEBUG || $exception instanceof UserException);

		if ($useErrorView && $this->errorAction !== null)
		{
			$result = Yii::$app->runAction($this->errorAction);
			if ($result instanceof Response)
			{
				$response = $result;
			}
			else
			{
				$response->data = $result;
			}
		}
		elseif ($response->format === Response::FORMAT_HTML)
		{
			if (isset($_SERVER['HTTP_X_REQUESTED_WITH']) && $_SERVER['HTTP_X_REQUESTED_WITH'] === 'XMLHttpRequest' || YII_ENV_TEST)
			{
				// AJAX request
				$response->data = '<pre>' . $this->htmlEncode($this->convertExceptionToString($exception)) . '</pre>';
			}
			else
			{
				// if there is an error during error rendering it's useful to
				// display PHP error in debug mode instead of a blank screen
				if (YII_DEBUG)
				{
					ini_set('display_errors', 1);
				}
				$file = $useErrorView ? $this->errorView : $this->exceptionView;
				$response->data = $this->renderFile($file, [
					'exception' => $exception,
				]);
			}
		}
		else
		{
			$response->data = $this->convertExceptionToArray($exception);
		}

		if ($exception instanceof HttpException)
		{
			$response->setStatusCode($exception->statusCode);
		}
		elseif ($exception instanceof UserException)
		{
			$response->setStatusCode(200);
		}
		else
		{
			$response->setStatusCode(500);
		}

		$response->send();
	}

	/**
	 * Converts an exception into an array.
	 * @param \Exception $exception the exception being converted
	 * @return array the array representation of the exception.
	 */
	protected function convertExceptionToArray($exception)
	{
		if (!YII_DEBUG && !$exception instanceof UserException && !$exception instanceof HttpException)
		{
			$exception = new HttpException(500, '服务器内部错误!');
		}

		$array = [
			//'name' => ($exception instanceof Exception || $exception instanceof ErrorException) ? $exception->getName() : 'Exception',
			'errmsg' => $exception->getMessage(),
			'errcode' => $exception->getCode() ? $exception->getCode() : 99,
		];

		if ($exception instanceof HttpException)
		{
			$array['status'] = $exception->statusCode;
		}
		if ($exception instanceof NotFoundHttpException)
		{
			$array['errcode'] = 104;
		}

		if (YII_DEBUG)
		{
			$array['type'] = get_class($exception);
			if (!$exception instanceof UserException)
			{
				$array['file'] = $exception->getFile();
				$array['line'] = $exception->getLine();
				$array['stack-trace'] = explode("\n", $exception->getTraceAsString());
				if ($exception instanceof \yii\db\Exception)
				{
					$array['error-info'] = $exception->errorInfo;
				}
			}
		}


		if (($prev = $exception->getPrevious()) !== null)
		{
			$array['previous'] = $this->convertExceptionToArray($prev);
		}

		return $array;
	}

	/**
	 * Converts special characters to HTML entities.
	 * @param string $text to encode.
	 * @return string encoded original text.
	 */
	public function htmlEncode($text)
	{
		return htmlspecialchars($text, ENT_QUOTES, Yii::$app->charset);
	}

	/**
	 * Adds informational links to the given PHP type/class.
	 * @param string $code type/class name to be linkified.
	 * @return string linkified with HTML type/class name.
	 */
	public function addTypeLinks($code)
	{
		if (preg_match('/(.*?)::([^(]+)/', $code, $matches))
		{
			$class = $matches[1];
			$method = $matches[2];
			$text = $this->htmlEncode($class) . '::' . $this->htmlEncode($method);
		}
		else
		{
			$class = $code;
			$text = $this->htmlEncode($class);
		}

		if (strpos($code, 'yii\\') !== 0)
		{
			return $text;
		}

		$page = $this->htmlEncode(strtolower(str_replace('\\', '-', $class)));
		$url = "http://www.yiiframework.com/doc-2.0/$page.html";
		if (isset($method))
		{
			$url .= "#$method()-detail";
		}

		return '<a href="' . $url . '" target="_blank">' . $text . '</a>';
	}

	/**
	 * Renders a view file as a PHP script.
	 * @param string $_file_ the view file.
	 * @param array $_params_ the parameters (name-value pairs) that will be extracted and made available in the view file.
	 * @return string the rendering result
	 */
	public function renderFile($_file_, $_params_)
	{
		$_params_['handler'] = $this;
		if ($this->exception instanceof ErrorException || !Yii::$app->has('view'))
		{
			ob_start();
			ob_implicit_flush(false);
			extract($_params_, EXTR_OVERWRITE);
			require(Yii::getAlias($_file_));

			return ob_get_clean();
		}
		else
		{
			return Yii::$app->getView()->renderFile($_file_, $_params_, $this);
		}
	}

	/**
	 * Renders the previous exception stack for a given Exception.
	 * @param \Exception $exception the exception whose precursors should be rendered.
	 * @return string HTML content of the rendered previous exceptions.
	 * Empty string if there are none.
	 */
	public function renderPreviousExceptions($exception)
	{
		if (($previous = $exception->getPrevious()) !== null)
		{
			return $this->renderFile($this->previousExceptionView, ['exception' => $previous]);
		}
		else
		{
			return '';
		}
	}

	/**
	 * Renders a single call stack element.
	 * @param string|null $file name where call has happened.
	 * @param integer|null $line number on which call has happened.
	 * @param string|null $class called class name.
	 * @param string|null $method called function/method name.
	 * @param integer $index number of the call stack element.
	 * @param array $args array of method arguments.
	 * @return string HTML content of the rendered call stack element.
	 */
	public function renderCallStackItem($file, $line, $class, $method, $args, $index)
	{
		$lines = [];
		$begin = $end = 0;
		if ($file !== null && $line !== null)
		{
			$line--; // adjust line number from one-based to zero-based
			$lines = @file($file);
			if ($line < 0 || $lines === false || ($lineCount = count($lines)) < $line + 1)
			{
				return '';
			}

			$half = (int) (($index == 1 ? $this->maxSourceLines : $this->maxTraceSourceLines) / 2);
			$begin = $line - $half > 0 ? $line - $half : 0;
			$end = $line + $half < $lineCount ? $line + $half : $lineCount - 1;
		}

		return $this->renderFile($this->callStackItemView, [
					'file' => $file,
					'line' => $line,
					'class' => $class,
					'method' => $method,
					'index' => $index,
					'lines' => $lines,
					'begin' => $begin,
					'end' => $end,
					'args' => $args,
		]);
	}

	/**
	 * Renders the request information.
	 * @return string the rendering result
	 */
	public function renderRequest()
	{
		$request = '';
		foreach (['_GET', '_POST', '_SERVER', '_FILES', '_COOKIE', '_SESSION', '_ENV'] as $name)
		{
			if (!empty($GLOBALS[$name]))
			{
				$request .= '$' . $name . ' = ' . VarDumper::export($GLOBALS[$name]) . ";\n\n";
			}
		}

		return '<pre>' . rtrim($request, "\n") . '</pre>';
	}

	/**
	 * Determines whether given name of the file belongs to the framework.
	 * @param string $file name to be checked.
	 * @return boolean whether given name of the file belongs to the framework.
	 */
	public function isCoreFile($file)
	{
		return $file === null || strpos(realpath($file), YII2_PATH . DIRECTORY_SEPARATOR) === 0;
	}

	/**
	 * Creates HTML containing link to the page with the information on given HTTP status code.
	 * @param integer $statusCode to be used to generate information link.
	 * @param string $statusDescription Description to display after the the status code.
	 * @return string generated HTML with HTTP status code information.
	 */
	public function createHttpStatusLink($statusCode, $statusDescription)
	{
		return '<a href="http://en.wikipedia.org/wiki/List_of_HTTP_status_codes#' . (int) $statusCode . '" target="_blank">HTTP ' . (int) $statusCode . ' &ndash; ' . $statusDescription . '</a>';
	}

	/**
	 * Creates string containing HTML link which refers to the home page of determined web-server software
	 * and its full name.
	 * @return string server software information hyperlink.
	 */
	public function createServerInformationLink()
	{
		$serverUrls = [
			'http://httpd.apache.org/' => ['apache'],
			'http://nginx.org/' => ['nginx'],
			'http://lighttpd.net/' => ['lighttpd'],
			'http://gwan.com/' => ['g-wan', 'gwan'],
			'http://iis.net/' => ['iis', 'services'],
			'http://php.net/manual/en/features.commandline.webserver.php' => ['development'],
		];
		if (isset($_SERVER['SERVER_SOFTWARE']))
		{
			foreach ($serverUrls as $url => $keywords)
			{
				foreach ($keywords as $keyword)
				{
					if (stripos($_SERVER['SERVER_SOFTWARE'], $keyword) !== false)
					{
						return '<a href="' . $url . '" target="_blank">' . $this->htmlEncode($_SERVER['SERVER_SOFTWARE']) . '</a>';
					}
				}
			}
		}

		return '';
	}

	/**
	 * Creates string containing HTML link which refers to the page with the current version
	 * of the framework and version number text.
	 * @return string framework version information hyperlink.
	 */
	public function createFrameworkVersionLink()
	{
		return '<a href="http://github.com/yiisoft/yii2/" target="_blank">' . $this->htmlEncode(Yii::getVersion()) . '</a>';
	}

	/**
	 * Converts arguments array to its string representation
	 *
	 * @param array $args arguments array to be converted
	 * @return string string representation of the arguments array
	 */
	public function argumentsToString($args)
	{
		$count = 0;
		$isAssoc = $args !== array_values($args);

		foreach ($args as $key => $value)
		{
			$count++;
			if ($count >= 5)
			{
				if ($count > 5)
				{
					unset($args[$key]);
				}
				else
				{
					$args[$key] = '...';
				}
				continue;
			}

			if (is_object($value))
			{
				$args[$key] = '<span class="title">' . $this->htmlEncode(get_class($value)) . '</span>';
			}
			elseif (is_bool($value))
			{
				$args[$key] = '<span class="keyword">' . ($value ? 'true' : 'false') . '</span>';
			}
			elseif (is_string($value))
			{
				$fullValue = $this->htmlEncode($value);
				if (mb_strlen($value, 'utf8') > 32)
				{
					$displayValue = $this->htmlEncode(mb_substr($value, 0, 32, 'utf8')) . '...';
					$args[$key] = "<span class=\"string\" title=\"$fullValue\">'$displayValue'</span>";
				}
				else
				{
					$args[$key] = "<span class=\"string\">'$fullValue'</span>";
				}
			}
			elseif (is_array($value))
			{
				$args[$key] = '[' . $this->argumentsToString($value) . ']';
			}
			elseif ($value === null)
			{
				$args[$key] = '<span class="keyword">null</span>';
			}
			elseif (is_resource($value))
			{
				$args[$key] = '<span class="keyword">resource</span>';
			}
			else
			{
				$args[$key] = '<span class="number">' . $value . '</span>';
			}

			if (is_string($key))
			{
				$args[$key] = '<span class="string">\'' . $this->htmlEncode($key) . "'</span> => $args[$key]";
			}
			elseif ($isAssoc)
			{
				$args[$key] = "<span class=\"number\">$key</span> => $args[$key]";
			}
		}
		$out = implode(", ", $args);

		return $out;
	}

	/**
	 * Returns human-readable exception name
	 * @param \Exception $exception
	 * @return string human-readable exception name or null if it cannot be determined
	 */
	public function getExceptionName($exception)
	{
		if ($exception instanceof \yii\base\Exception || $exception instanceof \yii\base\InvalidCallException || $exception instanceof \yii\base\InvalidParamException || $exception instanceof \yii\base\UnknownMethodException)
		{
			return $exception->getName();
		}
		return null;
	}

}
